ees 
384 Marcou’s Geological Map of the United States. 
lachians. The rocks of that peninsula, and on both sides of the 
Golden Gate, are chiefly sandstone and shale, and the same for- 
J 
. ras 
ae 
confined to the end of the peninsula, but is continied:southward 
to the western shores of t e Tulare lakes where the formations 
are chiefly miocene tertiary, the eruptive rocks s y 
n 
The romontory called Point Pinos, which forms the headland 
“of the Bay of Monterey, is represented as tertiary, while a por- 
hyritic granite constitutes the whole point and forms the coast- 
fing south to the Bay of San Carlos, and is probably continuous 
southward to San tas Obispo; forming a high and unbroken 
line of coast, all of which is colored tertiary on the map. 
ing the eye further south, we find the color denotin page D4 
tive and metamorphic rocks again usurping the whi 
should be colored tertiary, at Point Conception, which consists 
of beds of conglomerate and sandstone. J ghee hg 
The broad alluvial tract at the head of the Gulf of California 
—the Colorado desert—is made to extend nearly due north and 
parallel with the Colorado to the Soda Lake. ‘The published 
escription of this valley gives its direction as northwest. and 
southeast, extending to the foot of San Bernardine Mountain, 
* A former map by M. Marcou, published at Boston a little over two years nae 
Was reviewed in vol. xvii, of this Journal. The present map is in part open t 
< YieEaboaey Geological Report on the Pacific Railroad Route, surveyed by Lieut, 
a Williamson in California, House Doc, 129, Washington, D. ©, Jan. 1855. 
